There exist numerous connection terminals for electric wires that are of the type having a slit for stripping and retaining the wire, with such terminals being used, in particular, for connecting together or for connecting to equipment, electric wires for distributing power or for transmitting low current signals.
For example, such connection terminals may be of the junction block type, being designed to interconnect electric wires, e.g. in a distribution structure.
Such terminals may also be of the connector type enabling either some number of wires, e.g. from a multiconductor cable, to be connected to equipment including the connector, or else enabling some number of wires in one cable to be connected to wires in another cable, in series or in parallel.
In each case, at least one connection component includes a slit for stripping and retaining a wire, which slit is generally rectilinear, opening out at one end in a flared opening with sharp edges and extending beyond the opening in the form of a zone where the edges of the slit are at least approximately parallel.
A wire to be connected to such a component must be presented transversely relative to the slit so as to bear against the cutting edges of the wire-stripping opening, conventionally via the insulating sheath which covers the outside of the wire.
A pusher is generally provided for making the connection, with the pusher serving to thrust the core of the wire into the wire-retaining zone of the slit where the edges of said slit are at least approximately parallel, after having partially stripped the core of the wire during an initial engagement stage where the wire covering is in contact with the cutting edges of the flared opening that center the wire while simultaneously cutting through the covering in those regions of the covering that bear against the sharp edges.
The pusher is sometimes incorporated in the terminal and constitutes a portion thereof, but it is also possible for the pusher to be carried by an external hand-held tool, as disclosed, in particular, by European patent application No. 2 065 321, or else for the pusher to be mounted on a machine.
In conventional manner, the characteristics defining a connection component having a wire-stripping and wire-retaining slit depend to a large extent on the characteristics of the wire to be connected, and in particular on its section, particularly with respect to the size of the opening and of the gap between the edges of the slit in its wire-retaining zone where said edges are at least approximately parallel.
The dimensioning of the opening has an effect on the quality of the wire stripping in the region of the wire which is held in the wire-retaining zone of the slit, and consequently on the existence or otherwise of electrical contact between the core of the wire and the component in which it is held, and also on whether the core remains in one piece where it is held after it has been stripped.
Similarly, the gap between the edges of the slit must be designed to ensure that the core of the connected wire is held with sufficient force firstly to prevent the wire moving in the wire-retaining zone of the slit, and a fortiori preventing it from leaving said zone, while also preventing the wire-holding edges of the slit from cutting through the core, and secondly for ensuring sufficient contact pressure for electrical purposes under the conditions of use specified by the manufacturer.
As a result, many connection components having a slit for retaining and stripping a wire are made of a metal that is not very resilient so as to ensure that they are very rigid, and as a result they are suitable only for wires whose sections are very similar, e.g. one connector component may be suitable for wires of section 0.22 m.sup.2 to 0.34 mm.sup.2.
The manufacturers of connector components must therefore provide an entire series of components of different sizes to cover the range of wires that may be connected in this way, thus presenting several significant drawbacks, particularly with respect to manufacturing and costs.